Thread: Stamp repair - low temperature solder?

Hi Norm,

Is it possible to fill in the faulty letter with weld, and re-grind it before stamping I'm thinking tig would be ok on a low amp setting.

Regards
Ray

If you could post an image of the part concerned, a better assessment of the repair to be undertaken could be made.

Norm,

I can share in your grief. A few years ago, I made a table top for a Hercus rotary table base that had been kindly given to me by Hercus. My first attempt was relegated to the scrap box when I turned the mill feed handle the wrong way when cutting the final tee slot. The second attempt had proceeded well until the point of stamping the degree numerals. I found this to be hideously stressful, not aided by the Young Brothers stamps that I used. Was going o.k. till I punched 7 not 6..
There way no way that I was going to make table number three. I filed the number off and restamped it. The numbers are not evenly spaced but no worse than the hand stamped numbers on some of the other Hercus attachments that I have.

In all the other subsequent stamping operations that I've undertaken I've used a small piece of masking tape as a test marking surface. This facilitates some fine adjustment of the stamp before whacking it with a hammer. I also use a jig to align the stamp.

Is it feasible to file or remachine the surface and restamp?

Bob.

Hi again, thanks for the replies..

When I first made the mistake, among other things I said "bugger it, nobody will ever notice it". I proceeded to paint it and subsequently mounted the part.

True to my prediction, nobody has noticed - except me. I now have these neon arrows in the corner of my shed, flashing away, pointing at the dodge characters. I can't go past it without going over and taking another disgusted look!

Yes, I could remove the part and grind it all off and so on but I'd sure like to keep it simple. Besides who's to say I won't do the same (but different) mistake again.

I'd like to find a way to repair it. So, back to my soldering question.

In the dark ages, before they invented Bondo, autobody repair was done with solder. The repairman would tin the damaged panel and then with just enough torch heat to turn the solder bars to plastic, squish layers of solder onto the damaged part.

I'm thinking that I could repair those bad characters using the same method.

My question is should I use the low-temperature available to model railroaders or the plain ol' 60/40. Since it is a large iron part it'll act as a heat sink. So I might have trouble tinning it. There is no plastic step without the tinning.

Thanks, Norm

I am not sure what you mean by low temp solder, but I assume you mean a plumbers or electronic soft solder, as opposed to a silver solder.

Issues I see with a soft solder are:

1. A small iron (tip around 1/4inch or less) will not have sufficient thermal mass to heat the metal to allow solder to adhere and fill the indentation. A very large plumbers iron would be viable if the base material is less than 1.5mm thick, beyond that it would be swamped and inadequate.

2. If you need to restamp over the repair I suspect that there would be a high chance of the punch impact lifting the infill solder and releasing it at the time, or weakening the bond so that it fell out later.

A silver solder repair would be more effective long term provided that the article could handle the localised heating required to make the patch.

Which ever way you end up going, I would do a test piece first by stamping a piece of material of similar thickness and attempting to fill the indentation with the metal you intend to use. This way you have some practice and knowledge of the job before you attempt it on the real part, avoiding further damaging it if it does work as planned.

Edit. Further info in prev post. Panel beaters used a lead wipe to provide an easy to work surface coat. As you mentioned heat source was an oxy torch and the base panels were probably twice as thick as currently used.

The lower the melting point of the solder the weaker the material and the bond will be. I haven't used the low melt stuff you mentioned but am used to both soft and silver solder. I have doubts about soft solder and a lower melting point metal would be worse in my opinion.

Completely agree with malb.

Furthermore if your final finish is raw mild steel, solder will be a very different colour to mild steel, therefore hi-lighting your unfortunate error. Same goes for pretty much any other filler except mild steel. If you really want it (the error) gone, you might consider a touch with the arc, file off and restamp IMHO
Edit, Somehow I very much doubt you would make the same error again, but if you do...fix it again.

Another in line to agree. I soldered all my working life and you have to have both surfaces the same temperature. Also solder being lead + tarnishes and will look like a patch. Steel is quite difficult to solder simply because its not the best conductor of heat and to solder properly all the areas to be soldered must be above melting point. That is difficult with a small iron so your chances of not having solder flow to places you dont want are poor. Your solder would be electonic solder, plumbers solder would be too clagy. But it just wont work, my advice is weld and file.

Just use some metal reinforced bog, if it's an item that is painted.

Have you considered peining the offending letter and restamping! I have been correcting my mistakes this way for years ( aluminium and mild steel" lucky horseshoes") I use purpose shaped hammers but probaly it could be carefully done with dome shaped punches. Practice on some similar scrap steel and see if your happy with it?
I agee that soldering wont work and that welding on a finished surface without undercuts can be very difficult, unless your a well experianced welder!
Graeme